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/*
* IA32 helper functions
*
* Copyright (C) 1999 Arun Sharma <arun.sharma@intel.com>
* Copyright (C) 2000 Asit K. Mallick <asit.k.mallick@intel.com>
* Copyright (C) 2001 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
*
* 06/16/00 A. Mallick added csd/ssd/tssd for ia32 thread context
* 02/19/01 D. Mosberger dropped tssd; it's not needed
* 09/14/01 D. Mosberger fixed memory management for gdt/tss page
* 09/29/01 D. Mosberger added ia32_load_segment_descriptors()
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/personality.h>
#include <linux/sched.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/processor.h>
#include <asm/ia32.h>
extern void die_if_kernel (char *str, struct pt_regs *regs, long err);
struct exec_domain ia32_exec_domain;
struct page *ia32_shared_page[(2*IA32_PAGE_SIZE + PAGE_SIZE - 1)/PAGE_SIZE];
unsigned long *ia32_gdt;
static unsigned long
load_desc (u16 selector)
{
unsigned long *table, limit, index;
if (!selector)
return 0;
if (selector & IA32_SEGSEL_TI) {
table = (unsigned long *) IA32_LDT_OFFSET;
limit = IA32_LDT_ENTRIES;
} else {
table = ia32_gdt;
limit = IA32_PAGE_SIZE / sizeof(ia32_gdt[0]);
}
index = selector >> IA32_SEGSEL_INDEX_SHIFT;
if (index >= limit)
return 0;
return IA32_SEG_UNSCRAMBLE(table[index]);
}
void
ia32_load_segment_descriptors (struct task_struct *task)
{
struct pt_regs *regs = ia64_task_regs(task);
/* Setup the segment descriptors */
regs->r24 = load_desc(regs->r16 >> 16); /* ESD */
regs->r27 = load_desc(regs->r16 >> 0); /* DSD */
regs->r28 = load_desc(regs->r16 >> 32); /* FSD */
regs->r29 = load_desc(regs->r16 >> 48); /* GSD */
task->thread.csd = load_desc(regs->r17 >> 0); /* CSD */
task->thread.ssd = load_desc(regs->r17 >> 16); /* SSD */
}
void
ia32_save_state (struct task_struct *t)
{
unsigned long eflag, fsr, fcr, fir, fdr, csd, ssd;
asm ("mov %0=ar.eflag;"
"mov %1=ar.fsr;"
"mov %2=ar.fcr;"
"mov %3=ar.fir;"
"mov %4=ar.fdr;"
"mov %5=ar.csd;"
"mov %6=ar.ssd;"
: "=r"(eflag), "=r"(fsr), "=r"(fcr), "=r"(fir), "=r"(fdr), "=r"(csd), "=r"(ssd));
t->thread.eflag = eflag;
t->thread.fsr = fsr;
t->thread.fcr = fcr;
t->thread.fir = fir;
t->thread.fdr = fdr;
t->thread.csd = csd;
t->thread.ssd = ssd;
ia64_set_kr(IA64_KR_IO_BASE, t->thread.old_iob);
ia64_set_kr(IA64_KR_TSSD, t->thread.old_k1);
}
void
ia32_load_state (struct task_struct *t)
{
unsigned long eflag, fsr, fcr, fir, fdr, csd, ssd, tssd;
struct pt_regs *regs = ia64_task_regs(t);
int nr = smp_processor_id(); /* LDT and TSS depend on CPU number: */
nr = smp_processor_id();
eflag = t->thread.eflag;
fsr = t->thread.fsr;
fcr = t->thread.fcr;
fir = t->thread.fir;
fdr = t->thread.fdr;
csd = t->thread.csd;
ssd = t->thread.ssd;
tssd = load_desc(_TSS(nr)); /* TSSD */
asm volatile ("mov ar.eflag=%0;"
"mov ar.fsr=%1;"
"mov ar.fcr=%2;"
"mov ar.fir=%3;"
"mov ar.fdr=%4;"
"mov ar.csd=%5;"
"mov ar.ssd=%6;"
:: "r"(eflag), "r"(fsr), "r"(fcr), "r"(fir), "r"(fdr), "r"(csd), "r"(ssd));
current->thread.old_iob = ia64_get_kr(IA64_KR_IO_BASE);
current->thread.old_k1 = ia64_get_kr(IA64_KR_TSSD);
ia64_set_kr(IA64_KR_IO_BASE, IA32_IOBASE);
ia64_set_kr(IA64_KR_TSSD, tssd);
regs->r17 = (_TSS(nr) << 48) | (_LDT(nr) << 32) | (__u32) regs->r17;
regs->r30 = load_desc(_LDT(nr)); /* LDTD */
}
/*
* Setup IA32 GDT and TSS
*/
void
ia32_gdt_init (void)
{
unsigned long *tss;
unsigned long ldt_size;
int nr;
ia32_shared_page[0] = alloc_page(GFP_KERNEL);
ia32_gdt = page_address(ia32_shared_page[0]);
tss = ia32_gdt + IA32_PAGE_SIZE/sizeof(ia32_gdt[0]);
if (IA32_PAGE_SIZE == PAGE_SIZE) {
ia32_shared_page[1] = alloc_page(GFP_KERNEL);
tss = page_address(ia32_shared_page[1]);
}
/* CS descriptor in IA-32 (scrambled) format */
ia32_gdt[__USER_CS >> 3] = IA32_SEG_DESCRIPTOR(0, (IA32_PAGE_OFFSET-1) >> IA32_PAGE_SHIFT,
0xb, 1, 3, 1, 1, 1, 1);
/* DS descriptor in IA-32 (scrambled) format */
ia32_gdt[__USER_DS >> 3] = IA32_SEG_DESCRIPTOR(0, (IA32_PAGE_OFFSET-1) >> IA32_PAGE_SHIFT,
0x3, 1, 3, 1, 1, 1, 1);
/* We never change the TSS and LDT descriptors, so we can share them across all CPUs. */
ldt_size = PAGE_ALIGN(IA32_LDT_ENTRIES*IA32_LDT_ENTRY_SIZE);
for (nr = 0; nr < NR_CPUS; ++nr) {
ia32_gdt[_TSS(nr)] = IA32_SEG_DESCRIPTOR(IA32_TSS_OFFSET, 235,
0xb, 0, 3, 1, 1, 1, 0);
ia32_gdt[_LDT(nr)] = IA32_SEG_DESCRIPTOR(IA32_LDT_OFFSET, ldt_size - 1,
0x2, 0, 3, 1, 1, 1, 0);
}
}
/*
* Handle bad IA32 interrupt via syscall
*/
void
ia32_bad_interrupt (unsigned long int_num, struct pt_regs *regs)
{
siginfo_t siginfo;
die_if_kernel("Bad IA-32 interrupt", regs, int_num);
siginfo.si_signo = SIGTRAP;
siginfo.si_errno = int_num; /* XXX is it OK to abuse si_errno like this? */
siginfo.si_code = TRAP_BRKPT;
force_sig_info(SIGTRAP, &siginfo, current);
}
static int __init
ia32_init (void)
{
ia32_exec_domain.name = "Linux/x86";
ia32_exec_domain.handler = NULL;
ia32_exec_domain.pers_low = PER_LINUX32;
ia32_exec_domain.pers_high = PER_LINUX32;
ia32_exec_domain.signal_map = default_exec_domain.signal_map;
ia32_exec_domain.signal_invmap = default_exec_domain.signal_invmap;
register_exec_domain(&ia32_exec_domain);
return 0;
}
__initcall(ia32_init);
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